Welcome to the Washington ARTCC CWSU in Leesburg, VA Providing Real-Time Weather Support to AT Control Operations The Center Weather Service Unit is collocated with the Washington Air Route Traffic Control Center in Leesburg, VA. It's staff consists of four National Weather Service Meteorologists and is open from 5:30am to 9pm daily, seven days a week. Written, graphic and verbal weather briefings and updates are provided to the Traffic Management Unit and control room areas as well as the Potomac Traffic Radar Control and the tower supervisors. Forecast for the location, intensity, stating time, coverage and movement of thunderstorms aid in rerouting aircraft around hazardous weather. When necessary, the meteorologist issues a Center Weather Advisory: a short term (2 hours or less) warning of hazardous weather conditions similar to but more localized than the SIGMETs and Convective SIGMETs issued by the Aviation Weather Center.